1. Field of the Invention
The present invention relates to visual display input-output devices for head-mounted computer video system displays.
2. Description of the Relevant Art
Virtual reality can be described as a set of images, and sometimes sounds, that are generated by a computer and broadcast directly to a person who perceives them as an encompassing "reality". Often the apparatus used to broadcast the images to the person is a helmet shaped device worn over the head. This device often contains two small screens, one for each eye, a speaker for each ear, and some devices to track head movements. This is a large and heavy device that cannot be worn constantly during everyday activities.
Since these initial helmet like devices were introduced, more compact virtual reality appliances have been constructed or described. These would be devices such as: smaller lighter goggle or eyeglass sized devices which hold liquid crystal displays (LCD) over the eyes; eyeglass like devices equipped with LCDs and mirroring systems to display images on the lens part of the glasses; eyeglass like devices equipped with laser and mirroring systems that draw images directly on the retina of the eye thereby creating the illusion that the drawn image is floating in space directly ahead of the viewer; and others.
Computers are commonly used throughout the world and can have many different characteristics depending on their use. One type of computer is termed the "personal digital assistant" in the popular and trade press. This type of computer is typically portable and battery powered. An example of this type of computer is the Newton computer sold by Apple Computer Corporation.
A "personal digital assistant" type computer usually has a large LCD area for displaying output to the user. Very often this LCD area is also used as an input area to allow the user to issue commands and enter hand written information by touching and moving a stylus on this surface. The LCD display area contains electronic sensors that can track the location of the stylus tip and thereby sense its movements over the surface. Typically, as the stylus tip is moved across the LCD surface, a line is instantaneously displayed by the LCD which illuminates the exact path followed by the stylus.